1. Field of the Invention
The present invention relates generally to a multi-stage connector including a plurality of connector housings each having a plurality of crimping terminals received therein wherein a plurality of cables are brought in contact with the corresponding crimping blades held in the crimping terminals while each of the cables is covered with a sheath layer. More particularly, the present invention relates to improvement of a multi-stage connector of the foregoing type wherein a plurality of crimping terminals are arranged in the parallel relationship relative to each other at each stage, and moreover, a plurality of crimping terminals received at all the stages are located in alignment with each other in the vertical direction.
2. Description of the Related Art
In recent years, various kinds of connectors are practically used in many industrial fields for the purpose of electrically connecting cables to another cables or terminals in an electric equipment, an electronized vehicle or the like. Generally, each connector is constructed such that each terminal having a cable connected thereto is received in a connector housing. Otherwise, each connector is constructed such that a cable is electrically connected to another cable not via soldering or crimping but via pressure-contacting.
To facilitate understanding of the present invention, a typical conventional multi-stage connector of the foregoing type will be described below with reference to FIG. 7 to FIG. 9.
In the drawings, reference numeral 1 designates a connector housing. A plurality of terminal receiving chambers 2 are formed at the upper stage of the connector housing 1, and the front end wall of each terminal receiving chamber 2 and a part of the upper wall of the same in the vicinity of the foremost end of the connector housing 1 are cut out so as to form an opening portion 3. A crimp terminal 19 to be described later with reference to FIG. 8 is inserted into the corresponding terminal receiving chamber 2 through the opening portion 3, and thereafter, a cable to be described later is likewise inserted into the corresponding terminal receiving chamber 2 through the opening portion 3 by actuating an automatic feeding unit (not shown) so as to enable the terminal 19 to be crimped on the cable. Reference numerals 4 and 5 designate slide housings (male connector housings), respectively. The slide housings 4 and 5 are slidably inserted into the connector housing 1 not only at the middle stage but also as the lower stage of the same.
A fixing protuberance 6 and an engagement protuberance 7 are disposed on each side wall of the slide housings 4 and 5 while projecting outside of the side wall. To cooperate with the fixing protuberance 6 and the engagement protuberance 7, provisional engagement windows 8 and normal engagement windows 9 are formed through each side wall of the connector housing 1 while they are located in alignment with each other in the A arrow-marked direction.
Reference numeral 6a designates a fixing protuberance disposed on each side wall of the connector housing 1. With this construction, when the slide housings 4 and 5 are inserted into the connector housing 1, the fixing protuberances 6a and 6 are located in alignment with each other in the vertical direction.
Reference numeral 12 designates a housing cover. A plurality of fixing/engaging windows 13 are formed through the housing cover 12. When the fixing protuberances 6a and 6 are engaged with the fixing/engagement windows 13, the opening portion 3 of the connector housing 1 is closed with an upper wall 14 of the housing cover 12.
Next, an assembling operation to be performed for the conventional multi-stage connector constructed in the aforementioned manner will be described below.
While the slide housing 5 located at the lower stage is held in the provisionally engaged state (wherein the engagement protuberances 7 are engaged with the provisional engagement windows 8), a cable 15 is inserted into the opponent terminal 19 which in turn is crimped on the cable 15 from above by actuating an automatic feeding unit (not shown), causing the cable 15 to be electrically connected to the crimp terminal 16 via the terminal 16. Subsequently, the slide housing 5 is slidably squeezed in the connector housing 1 until the engagement protuberances 7 are engaged with the normal engagement windows 9.
Next, the slide housing 4 located at the middle stage is held in the provisionally engaged state (wherein the engagement protuberances 7 are engaged with the provisional engagement windows 8), and subsequently, a cable 15 is brought in contact with a terminal 16 from above by actuating the automatic feeding unit (not shown) so as to allow the terminal 16 to be crimped on the cable 15 for making electrical connection therebetween. Thereafter, the slide housing 4 is slidably squeezed in the connector housing 1 so that the engagement protuberances 7 on the slide housing 5 are engaged with the normal engagement window 9. It is obvious that another cable 15 is likewise brought in contact with a terminal 16 received in the receiving chamber 2 of the connector housing 1 from above so as to allow the terminal 16 to be crimped on the cable 15 in the same manner as mentioned above for making electrical connection to a crimp terminal 19 via the thus crimped terminal 16.
A squeezing operation (closing operation) is performed for the slide housings 4 and 5 in the A arrow-marked direction by actuating an automatic squeezing unit (not shown), while a drawing operation is performed for the same in the B arrow-marked direction by actuating the foregoing automatic squeezing unit. In FIG. 8, reference numeral 17 designates a guide wall. The guide wall 17 is constructed such that a male terminal insert hole 18 is formed through the rear wall of each terminal receiving chamber 2 so as to allow a male terminal (not shown) to be fitted thereinto.
As shown in FIG. 9, while the connector housing 1 is assembled with the aforementioned components, the fixing projections 6a and 6 are engaged with the engagement windows 13 so as to prevent the slide housings 4 and 5 from being disconnected from the connector housing 1.
With the conventional multi-stage connector constructed in the above-described manner, since each assembling operation can automatically be performed in that way with the aid of the foregoing automatic units (not shown), it can be achieved at a high efficiency. Another advantageous effect is that the number of crimp terminals to be received in the connector housing in the multi-staged state can arbitrarily be increased.
However, since the conventional multi-stage connector is not provided with any type of cable retaining means, when a certain intensity of mechanical power is applied to the crimped part of the terminal, incorrect electrical contacting is liable to occur with the multi-stage connector. To assure that the multi-stage connector is provided with cable retaining means, it should unavoidably be constructed with larger dimensions because of a necessity for preparing a certain space for receiving the cable retaining means therein.
In addition, in the case that a certain intensity of cable pulling power is exerted on a bundle of cables in such a direction that it is drawn out of the connector housing, since the conventional multi-stage connector does not include any means for standing against the cable pulling power, the intensity of cable holding power exerted on the terminal at the crimped part of the latter is undesirably reduced. Also in this case, a malfunction of incorrect electrical contacting is liable to occur with the multi-stage connector.